Nanoscale-sized materials have recently been in the spotlight due to their distinctive electrical, optical, and mechanical characteristics. Researches so far conducted on nanostructures show that, on account of new phenomena such as quantum size effects, they are applicable for new optical devices in the future. In particular, such nanostructures can be used not only for single electron transistor devices but also for various chemical sensors and biosensors, and thus are receiving more attention.
Detection of target materials using a biosensor including a nanostructure is implemented in such a manner that a receptor fixed on a surface of the nanostructure is allowed to adsorb target materials (chemical markers, biomolecules, or disease-specific markers) on the surface of the nanostructure, and the adsorbed target materials cause a change in the conductivity of the nanostructure.
This change in the conductivity of the nanostructure may be used to detect target materials in a human body, for example, plasma proteins in a diabetic patient.
Diabetes is a kind of metabolic disease in which the amount of insulin produced by pancreas is insufficient or insulin does not properly function. Diabetic patients should undergo diet therapy, exercise therapy, drug therapy, and the like in order to manage their blood sugar levels. Therefore, the diabetic patients are required to regularly measure the sugar levels every day to get the above therapies.
According to a conventional method of determining a blood sugar level, a small quantity of blood sample obtained by pricking a finger of a patient is put in a chemically treated sensor to measure the blood sugar level. Such a method has been disclosed in Korean Laid-open Patent Publication No. 2010-0086039 or the like.
The above conventional method of determining a blood sugar level entails frequent blood collection, which inflicts pain on patients and causes problems such as bacterial infection and the like. Moreover, since it takes some time to put a blood sample in a chemically treated sensor, an error may occur in the measurement of the blood sugar level. Therefore, there have been continuous demands for developing methods that may more accurately measure sugar levels of diabetic patients in real time without blood collection.